The present invention relates to an image input apparatus which can effectively detect various commands on a platen glass.
In some image input apparatuses such as a copier, a touch-panel is formed on the upper surface of a platen cover and an edit function is provided in the panel. In this type of apparatus, the platen cover is closed, a document is placed on the platen cover and then, the edit function is used. After the edit function has been used, the document is placed again on the platen glass and an image input operation is carried out.
The touch-panel of the editor for this kind of input apparatus is an electrostatic capacitance type panel. For an operational unit, generally, a resistance film type touch-panel is most frequently used.
The electrostatic capacitance type touch panel operators as follows: a finger contact point on the surface of the glass, on which conductive films are evaporated, is detected by a weak current flowing from sensors provided on four corners of the glass surface at the contact point. However, the following problem occurs: the value of the electrostatic capacitance differs depending on each human user therefore some corrections are necessary.
The resistance film type touch-panel operates as follows: a transparent conductive thin film formed on the glass surface or a polyester film forms an electrode, and a voltage drop on the surface of the electrode provides the position detection.
Further, in some cases, an optical method is used for the touch-panel. In this method, position detection is provided when light rays (infrared rays) between a pair of light emitting/light receiving diodes are interrupted by fingers or the like. In this method, an exclusive frame for diode mounting is necessary. Further, since light rays pass several centimeters above the surface of the touch panel, a direction signal is input to the sensor before fingers touch the panel. This creates a problem, because the operation can not be smoothly carried out.
In the apparatus with the foregoing editor, the document is placed on the platen cover, a position and area of the document is input the platen cover is opened, the document is placed on the platen glass, and a document image is input to the apparatus. Accordingly, this operation is troublesome.
Further, an automatic document feeder (ADF) can not be used together with the editor of the apparatus. Therefore, when the automatic document feeder is used in the apparatus, the editor must be provided separately from the apparatus. Accordingly, the poor space efficiency creates a problem.
The object of the present invention is to solve the foregoing problems, and to realize an image input apparatus which can give various commands from the surface of the platen glass.